.\" Copyright (c) 1980 Regents of the University of California.
.\" All rights reserved.  The Berkeley software License Agreement
.\" specifies the terms and conditions for redistribution.
.\"
.\"	@(#)dr.4	6.2.1 (2.11BSD) 1996/1/27
.\"
.TH DR 4 "January 27, 1996"
.UC 2
.SH NAME
dr \- DR11-W general purpose interface driver
.SH SYNOPSIS
.ft B
.nf
/sys/conf/SYSTEM:
	NDR	\fIdr11-w_units\fP	# DR11-W

/etc/dtab:
.ta .5i +\w'#Name 'u +\w'Unit# 'u +\w'177777 'u +\w'Vector 'u +\w'Br 'u +\w'xxxxxxx 'u +\w'xxxxxxx 'u
	#Name	Unit#	Addr	Vector	Br	Handler(s)		# Comments
	dr	?	172410	124	5	drintr		# dr11-w (b-bus emulator)
	dr	?	172430	130	5	drintr		# dr11-w (gc-bus emulator)
	dr	?	172450	134	5	drintr		# dr11-w (em-2 interface)
.DT

major device number(s):
	raw: 12
minor device encoding:
	bits 0007 specify DR unit
.fi
.ft R
.SH DESCRIPTION
The
.I "Digital Equipment 1981-82 Peripherals Handbook"
states the following about the DR11-W:
.RS
.PP
The The DR11-W is a general purpose, direct memory access (DMA) interface to
the PDP-11 UNIBUS or VAX UNIBUS.  The DR11-W moves data directly between
memory and the UNIBUS to and from the user's peripheral.
.PP
It features:
.IP \(bu
Word or byte transfers.
.IP \(bu
Programmed or direct memory access (DMA) block transfers.
.IP \(bu
Burst data transfers.
.IP \(bu
User-controlled transfer rates up to memory speed.
.PP
The DR11-W is a 53-line direct memory access (DMA) interface to the PDP-11
UNIBUS or VAX UBA, which allows the user to control data transfers between
the host processor and a peripheral.  The DR11-W has 32 data lines (for
transferring 16-bit parallel data) and 21 control lines (for transferring
control and status information.
.PP
When used as an interprocessor buffer (IPB), the DR11-W allows
data transfers between two processors.  Interprocessor communication is
accomplished by attaching one DR11-W to each processor UNIBUS
or UBA and then cabling the two DR11-Ws together.
.RE
.PP
There.  Now you know as much about it as I do.
.PP
A number of \fIioctl\fP(2) calls apply to the dr devices, and
have the form
.RS
.nf
.ft B
#include <pdpuba/drreg.h>
ioctl(fildes, code, arg)
int *arg;
.ft R
.fi
.RE
The applicable codes are:
.IP DRGTTY 18
Get DR11-W status.
.IP DRSTTY 18
Set flags and function.
.IP DRSFUN 18
Set function.
.IP DRSFLAG 18
Set flags.
.IP DRGCSR 18
Get CSR and WCR.
.IP DRSSIG 18
Set signal for ATTN interrupt.
.IP DRESET 18
Reset DR11-W interface.
.IP DRSTIME 18
Set timeout.
.IP DRCTIME 18
Set timeout inactive.
.IP DROUTPUT 18
Put word in output data register.
.IP DRINPUT 18
Get word from input data register.
.IP DRITIME 18
Don't ignore errors on timeout.
.SH FILES
.ta \w'/dev/MAKEDEV.local  'u
/dev/dr[0-7]	device special files
.br
/dev/MAKEDEV	script to create special files
.br
/dev/MAKEDEV.local	script to localize special files
.DT
.SH "SEE ALSO"
dtab(5),
autoconfig(8)
.SH DIAGNOSTICS
\fBdr%d: error csr=%b, eir=%b\fR
.PP
\fBdr%d: timeout error\fR
.SH BUGS
This interface is only available under 2.9BSD and 2.11BSD.  No documentation
exists on how to use it.
